Move services code brought in from Mojo to live under //third_party.

mojo/services/native_viewport/public/interfaces/native_viewport.mojom

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-module mojo;
-
-import "geometry/public/interfaces/geometry.mojom";
-import "gpu/public/interfaces/command_buffer.mojom";
-import "input_events/public/interfaces/input_events.mojom";
-import "surfaces/public/interfaces/surface_id.mojom";
-
-struct ViewportMetrics {
-  Size size;
-  float device_pixel_ratio = 1.0;
-};
-
-interface NativeViewport {
-  // TODO(sky): having a create function is awkward. Should there be a factory
-  // to create the NativeViewport that takes the size?
-  Create(Size size) => (uint64 native_viewport_id, ViewportMetrics metrics);
-
-  Show();
-  Hide();
-  Close();
-  SetSize(Size size);
-  SubmittedFrame(SurfaceId surface_id);
-  SetEventDispatcher(NativeViewportEventDispatcher dispatcher);
-
-  // The initial viewport metrics will be sent in the reply to the Create
-  // method. Call RequestMetrics() to receive updates when the viewport metrics
-  // change. The reply will be sent when the viewport metrics are different from
-  // the values last sent, so to receive continuous updates call this method
-  // again after receiving the callback.
-  RequestMetrics() => (ViewportMetrics metrics);
-};
-
-interface NativeViewportEventDispatcher {
-  OnEvent(Event event) => ();
-};